Hydraulic slave cylinders disposed concentrically on the transmission input shaft, the so-called CSC, are known and are already in operation in diverse embodiments in vehicles. In all embodiments, the objective is to hydraulically pressurize a working piston, executed as an annular piston, which is axially movable within a working chamber with a force for actuating a clutch, for instance, in order to separate the latter. This force is transmitted to a release bearing connected with the piston, whereby its clutch or its rotating diaphragm spring finger on the next disposed ring is in contact with the latter.
In these embodiments the pressure chamber is located in direct proximity of the release bearing. These slave cylinders are disposed between the clutch and transmission, thus outside the clutch housing.
In case of lack of space between the clutch and transmission, it is moreover known to integrate the actuator for the clutch or at least the release bearing that is in operative connection with the diaphragm spring fingers inside the clutch housing, wherein the corresponding pressure chamber is located outside the clutch. The connection between the release bearing disposed inside the clutch housing, about the transmission input shaft and the axially movable piston inside the pressure chamber, is established via a coupling element, for instance, an push rod. This push rod thereby acts, depending upon the applied clutch, as a tension or compression rod.
For the development of the force required for actuating the clutch, on the one hand a correspondingly large hydraulic surface area is required, upon which the size of the pressure chamber depends and on the other hand the seal of the pressure chamber against its surrounding is of great importance.